Audio problem: Nancy is watching 'The Evil Dead' in order to stay awake, but the audio of the film heard doesn't match with what scene is playing on the TV. (00:33:10)
Audio problem: When Nancy wakes up from her dream at the Dream Clinic, the doctor tries to give her a shot and you hear the nurse say "This will help you sleep", but the nurse's mouth is closed.
Audio problem: When the police pull up and run over to arrest Rod, he says "I'm cool, I'm cool!" His mouth doesn't move when this is said. (00:21:45)
Audio problem: When Tina is being attacked by Freddy Krueger just as she is trying to open the door to her house, she yells, "Nancy. Open the door. Nancy.", but her lips do not match with what she is saying. (00:16:50)
Audio problem: When Rod Lane runs away from Lt. Thompson, who is trying to arrest him, Lt. Thompson yells "Hold it," but his lips did not move. (00:22:30)
Answer: The scene you are referring to is a dream sequence. In dreams everything is different and how they change throughout the movie is no mistake.
SAZOO1975